Phase change memory cell with crystalline structure aligned to seed layer

A phase-change memory array, comprising:

• a plurality of horizontal lines;
• a plurality of vertical lines intersecting the plurality of horizontal lines at a plurality of cell locations;
• a plurality of phase-change memory cells located at each of said plurality of cell locations;
• and
• a plurality of transistors associated with each of the plurality of phase-change memory cells;
• wherein each of the phase-change memory cells comprises:
• an insulating layer;
• a first electrode embedded in the insulating layer, wherein an outer end of the first electrode is locally flush with an outer surface of the insulating layer;
• a second electrode, larger than the first electrode, and spaced from the first electrode;
• a compositionally homogenous crystalline phase change material layer;
• and
• a highly oriented seed layer, wherein a crystal structure of the homogenous phase change material layer is correlated with a crystal structure of the highly oriented seed layer;
• wherein the compositionally homogenous phase change material layer and the highly oriented seed layer are located at least partially between the first and second electrodes.

A method of forming a phase-change memory cell, comprising:

• providing a starting structure comprising a substrate, an insulating layer outward of the substrate, and a first electrode embedded in the insulating layer, wherein an outer end of the first electrode is locally flush with an outer surface of the insulating layer;
• depositing a highly oriented crystalline seed layer on an outer surface of the insulating layer and the outer end of the first electrode;
• epitaxially growing a compositionally homogenous crystalline phase change material layer on the highly oriented crystalline seed layer;
• and
• depositing a top electrode material on the compositionally homogenous crystalline phase change material layer.

A method of forming a phase-change memory cell, comprising:

• providing a starting structure comprising a substrate, an insulating layer outward of the substrate, and a first electrode embedded in the insulating layer, wherein an outer end of the first electrode is locally flush with an outer surface of the insulating layer;
• depositing an amorphous phase change material layer on an outer surface of the insulating layer and the outer end of the first electrode;
• depositing a highly oriented crystalline seed layer on an outer surface of the amorphous phase change material layer at a temperature below a crystallization temperature of the first amorphous phase change material layer, to produce a resultant structure;
• and
• annealing the resultant structure at a temperature above the crystallization temperature of the first amorphous phase change material layer to induce a solid phase crystallization of the amorphous phase change material layer by templating from the seeding layer.

A method of forming a phase-change memory cell, comprising:

• providing a starting structure comprising a substrate, an insulating layer outward of the substrate, and a first electrode embedded in the insulating layer, wherein an outer end of the first electrode is locally flush with an outer surface of the insulating layer and the insulating layer is amorphous;
• preparing an outer surface of the amorphous insulating layer to cause orientation of a subsequently epitaxially grown a compositionally homogenous crystalline phase change material layer;
• epitaxially growing the compositionally homogenous crystalline phase change material layer on the prepared outer surface of the amorphous insulating layer at a temperature such that compositionally homogenous crystalline phase change layer grows in a crystalline manner;
• and
• depositing a top electrode material on the compositionally homogenous crystalline phase change material layer.